Crafty Crows Can Build Tools From Memory

iStock
iStock

Scientists have discovered yet another reason to never get on a crow's bad side. According to new research reported by Gizmodo, members of at least one crow species can build tools from memory, rather than just copying the behavior of other crows—adding to the long list of impressive skills that set these corvids apart.

For the new study, published in the journal Scientific Reports, an international team of scientists looked at New Caledonian crows, a species known for its tool usage. New Caledonian crows use sticks to pick grubs out of logs, sometimes stashing these twigs away for later. Tools are so important to their lifestyle that their beaks even evolved to hold them. But how exactly the crows know to use tools—that is, whether the behavior is just an imitation or knowledge passed down through generations—has remained unclear until now.

The researchers set up the experiment by teaching eight crows to drop pieces of paper into a box in exchange for food. The birds eventually learned that they would only be rewarded if they dispensed either large sheets of paper measuring 40-millimeters-by-60 millimeters or smaller sheets that were 15-millimeters-by-25 millimeters. After the crows had adapted and started using sheets of either size, all the paper was taken away from them and replaced with one sheet that was too big for the box.

The crows knew exactly what to do: They ripped up the sheet until it matched one of the two sizes they had used to earn their food before and inserted it into the dispenser. They were able to do this with out looking at the sheets they had used previously, which suggests they had access to a visual memory of the tools. This supports the "mental template matching" theory—a belief among some crow experts that New Caledonian crows can form a mental image of a tool just by watching another crow use it and later recreate the tool on their own, thus passing along the template to other birds including their own offspring.

This is the first time mental template matching has been observed in birds, but anyone familiar with crow intelligence shouldn't be surprised: They've also been known to read traffic lights, recognize faces, nurse grudges, and hold funerals for their dead.

[h/t Gizmodo]

Why Do Ants Die After the Queen Dies?

iStock
iStock

Eduardo Fox:

A fundamental fact about social Hymenoptera (wasps, ants) that most people, including entomologists, are unaware of: They cannot live without their larvae.

Next time you see an ant’s nest, a bee hive, or a hornet’s nest, remember: That structure is essentially a neonatal ICU!

Why? Look at an ant’s body below:


Clker.com via Quora

Did you notice the waist? I tell you: The individual’s stomach is located after the thin waist. That means an ant cannot eat solids.

Now, take a look at an ant’s larva (a & b, below):


Notice the waist? There’s none. It means larvae eat solid food!

So, this is what happens: Ants are working hard together in that nest mainly to bring up hundreds of babies. They come out to get food and bring it back to the nest, then they chew it up and place it on their larvae. Larvae will swallow and digest the food for them. Especially protein. Larvae secrete nutrient-rich liquids back to the ants, which is their main source of amino acids and fatty acids.

Who lays eggs to produce larvae? Queens.*

What happens when queens die? No eggs, hence no larvae.

What happens when there are no larvae? Bad nutrition, ultimately no reason for the nest. Ants gradually get disorganized, and after a few weeks they die.

Wasps and more "primitive" ants can more easily produce a new queen who will be the next mated female in the hierarchy. However, if none of them is fertile enough and mated, the nest won’t last long. Bees work differently.

* Important technical notice: Queens normally live longer than workers. Nowhere in this answer did I mean to imply that larvae can somehow enable workers to live as long as queens!

This post originally appeared on Quora. Click here to view.

Watch a Gulper Eel Inflate Like a Terrifying Balloon

OET, NautilusLive.org
OET, NautilusLive.org

Since launching in 2008, the Ocean Exploration Trust's Nautilus research vessel has live-streamed a purple orb, a transparent squid, and a stubby octopus from the bottom of the ocean. The latest bizarre example of marine life captured by the vessel is a rare gulper eel that acts like a cross between a python and a pufferfish.

As Thrillist reports, this footage was shot by a Nautilus rover roaming the Pacific Ocean's Papahanaumokuakea Marine National Monument 4700 feet below the surface. In it, a limbless, slithery, black creature that looks like it swallowed a beach ball can be seen hovering above the sea floor. After about a minute, the eel deflates its throat, swims around for a bit, and unhinges its jaw to reveal a gaping mouth.

The reaction of the scientists onboard the ship is just as entertaining as the show the animal puts on. At first they're not sure what they're looking at ("It looks like a Muppet," someone says), and after being blown away by its shape-shifting skills, they conclude that it's a gulper eel. Gulper eels are named for their impressive jaw span, which allows them to swallow prey much larger than themselves and puff up to intimidate predators. Because they like to lurk at least 1500 feet beneath the ocean's surface, they're rarely documented.

You can watch the inflated eel and hear the researchers' response to it in the video below.

[h/t Thrillist]

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